I'd say that both are about nuisances. The Moth's Plea, by Elizabeth Jennings, is form the moth's perspective at being a pest, and it is given in a way so that you pity the moth. However, the poem Weasels by John Tripp gives the human's perspective on weasels, which are also pests. It gives every negative aspect about weasels so you come to despise them. In conclusion, the Moth's Plea is about pitying the pest, while Weasels is about shaming and hating on the pest.